COMPMID-1327: Add support for BBoxTransform operator in CL

Change-Id: I91865506166951b3bf7f06a0b2d4cde925cfefb6
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/153447
Tested-by: bsgcomp <bsgcomp@arm.com>
Reviewed-by: Pablo Tello <pablo.tello@arm.com>
diff --git a/arm_compute/core/CL/CLKernels.h b/arm_compute/core/CL/CLKernels.h
index 95b6f9b..298cf52 100644
--- a/arm_compute/core/CL/CLKernels.h
+++ b/arm_compute/core/CL/CLKernels.h
@@ -37,6 +37,7 @@
 #include "arm_compute/core/CL/kernels/CLBitwiseNotKernel.h"
 #include "arm_compute/core/CL/kernels/CLBitwiseOrKernel.h"
 #include "arm_compute/core/CL/kernels/CLBitwiseXorKernel.h"
+#include "arm_compute/core/CL/kernels/CLBoundingBoxTransformKernel.h"
 #include "arm_compute/core/CL/kernels/CLBox3x3Kernel.h"
 #include "arm_compute/core/CL/kernels/CLCannyEdgeKernel.h"
 #include "arm_compute/core/CL/kernels/CLChannelCombineKernel.h"
diff --git a/arm_compute/core/CL/kernels/CLBoundingBoxTransformKernel.h b/arm_compute/core/CL/kernels/CLBoundingBoxTransformKernel.h
new file mode 100644
index 0000000..6f0abc1
--- /dev/null
+++ b/arm_compute/core/CL/kernels/CLBoundingBoxTransformKernel.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2018 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef __ARM_COMPUTE_CLBOUNDINGBOXTRANSFORMKERNEL_H__
+#define __ARM_COMPUTE_CLBOUNDINGBOXTRANSFORMKERNEL_H__
+
+#include "arm_compute/core/CL/ICLKernel.h"
+
+namespace arm_compute
+{
+class ICLTensor;
+
+/** Interface for the bounding box kernel */
+class CLBoundingBoxTransformKernel : public ICLKernel
+{
+public:
+    /** Default constructor */
+    CLBoundingBoxTransformKernel();
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    CLBoundingBoxTransformKernel(const CLBoundingBoxTransformKernel &) = delete;
+    /** Prevent instances of this class from being copied (As this class contains pointers) */
+    CLBoundingBoxTransformKernel &operator=(const CLBoundingBoxTransformKernel &) = delete;
+    /** Allow instances of this class to be moved */
+    CLBoundingBoxTransformKernel(CLBoundingBoxTransformKernel &&) = default;
+    /** Allow instances of this class to be moved */
+    CLBoundingBoxTransformKernel &operator=(CLBoundingBoxTransformKernel &&) = default;
+    /** Default destructor */
+    ~CLBoundingBoxTransformKernel() = default;
+
+    /** Set the input and output tensors.
+     *
+     * @param[in]  boxes      Source tensor. Bounding box proposals in pixel coordinates. Size(M, 4), format [x1, y1, x2, y2]. Data types supported: F16/F32.
+     * @param[out] pred_boxes Destination tensor. Pixel coordinates of the transformed bounding boxes. Size (M, 4*K), format [x1, y1, x2, y2]. Data types supported: Same as @p input
+     * @param[in]  deltas     Bounding box translations and scales. Size (M, 4*K), format [dx, dy, dw, dh], K  is the number of classes. Data types supported: Same as @p input
+     * @param[in]  info       Contains BoundingBox operation information described in @ref BoundingBoxTransformInfo.
+     *
+     * @note Only single image prediction is supported. Height and Width (and scale) of the image will be contained in the BoundingBoxTransformInfo struct.
+     *
+     */
+    void configure(const ICLTensor *boxes, ICLTensor *pred_boxes, const ICLTensor *deltas, const BoundingBoxTransformInfo &info);
+
+    /** Static function to check if given info will lead to a valid configuration of @ref CLBoundingBoxTransform
+     *
+     * @param[in] boxes      Source tensor info. Bounding box proposals in pixel coordinates. Size(M, 4), format [x1, y1, x2, y2]. Data types supported: F16/F32.
+     * @param[in] pred_boxes Destination tensor info. Pixel coordinates of the transformed bounding boxes. Size (M, 4*K), format [x1, y1, x2, y2]. Data types supported: Same as @p input
+     * @param[in] deltas     Bounding box translations and scales. Size (M, 4*K), format [dx, dy, dw, dh], K  is the number of classes. Data types supported: Same as @p input
+     * @param[in] info       Contains BoundingBox operation information described in @ref BoundingBoxTransformInfo.
+     *
+     * @note Only single image prediction is supported. Height and Width (and scale) of the image will be contained in the BoundingBoxTransformInfo struct.
+     *
+     * @return a Status
+     */
+    static Status validate(const ITensorInfo *boxes, const ITensorInfo *pred_boxes, const ITensorInfo *deltas, const BoundingBoxTransformInfo &info);
+
+    // Inherited methods overridden:
+    void run(const Window &window, cl::CommandQueue &queue) override;
+
+private:
+    const ICLTensor *_boxes;
+    ICLTensor       *_pred_boxes;
+    const ICLTensor *_deltas;
+};
+} // namespace arm_compute
+#endif /*__ARM_COMPUTE_CLBOUNDINGBOXTRANSFORMKERNEL_H__ */
diff --git a/arm_compute/core/Types.h b/arm_compute/core/Types.h
index 8a8cd50..5e04bcd 100644
--- a/arm_compute/core/Types.h
+++ b/arm_compute/core/Types.h
@@ -851,6 +851,64 @@
     unsigned int _sampling_ratio;
 };
 
+/** Bounding Box Transform information class */
+class BoundingBoxTransformInfo
+{
+public:
+    /** Constructor
+     *
+     * @param[in] img_width       Width of the original image
+     * @param[in] img_height      Height, of the original image
+     * @param[in] scale           Scale of the original image
+     * @param[in] apply_scale     (Optional)Re-apply scaling after transforming the boxes. Defaults to false
+     * @param[in] weights         (Optional)Weights [wx, wy, ww, wh] for the deltas. Defaults to all ones
+     * @param[in] bbox_xform_clip (Optional)Minimum bounding box width and height after bounding box transformation in log-space. Defaults to log(1000/16)
+     */
+    BoundingBoxTransformInfo(float img_width, float img_height, float scale, bool apply_scale = false, const std::array<float, 4> weights = { 1.0, 1.0, 1.0, 1.0 }, float bbox_xform_clip =
+                                 4.135166556742356)
+        : _img_width(img_width), _img_height(img_height), _scale(scale), _apply_scale(apply_scale), _weights(weights), _bbox_xform_clip(bbox_xform_clip)
+    {
+    }
+
+    std::array<float, 4> weights() const
+    {
+        return _weights;
+    }
+
+    float bbox_xform_clip() const
+    {
+        return _bbox_xform_clip;
+    }
+
+    float img_height() const
+    {
+        return _img_height;
+    }
+
+    float img_width() const
+    {
+        return _img_width;
+    }
+
+    float scale() const
+    {
+        return _scale;
+    }
+
+    bool apply_scale() const
+    {
+        return _apply_scale;
+    }
+
+private:
+    float _img_width;
+    float _img_height;
+    float _scale;
+    bool  _apply_scale;
+    std::array<float, 4> _weights;
+    float _bbox_xform_clip;
+};
+
 /** Activation Layer Information class */
 class ActivationLayerInfo
 {